I used to have really bad, uncontrollable thoughts. I think what helped me the most was to "retrain" my brain! I learned to write down the negative thought and replace it with a positive one. We don't realize how we can spiral into a negative thinking trap! Replacing the thoughts with positive ones takes some practice, but like anything...you brain will get used to it. Here is a really good article....Hope this helps!
https://psychcentral.com/lib/replacing-your-neg...

When my thoughts want to be a runaway train, I color and listen to music. I'm 41 and feel silly that coloring helps, but it does. Maybe it'll help you too.

Thanks for the article on retraining your brain. I am going to read it and start trying this.

I get into the bad thoughts. Really feel them. Think about them. Think of things I might have said/done differently but obviously did not. Listen to music that heightens the sadness. Close my eyes and live in it. Somehow, this makes me feel better. I don't want to forget the bad thoughts, I just don't want them to bother me so much.

Try to meditate or write down your thoughts. Breath and relax. I know it sounds hard but it does work. I have the same issue. My mind is constantly going. Keeping a journal helps, letting your thoughts out on paper sometimes relieves what you are feeling in your mind. Seeing on paper also helps it to make sense.If the thoughts keep coming , call someone.